Photographic shutter



0t 23, l945- IB. GEHMLICH PHOTOGRAPHIG SHUTTER Filed NOV. 16, 1940Patented Oct. 23, 1945 PHOTOGRAPHIC SHUTTER Bruno Gehmlich, Freital 1,near Dresden, Germany; vested in the Alien Property CustodianApplication November 16, 1940, Serial No. 365,963 In Germany November28, 1939 e claims. (c1. lei- 26) Y The invention relates to improvementsin photographic shutters and particularly is directed to curtainshutters, also known as focal plane shutters.

It is an object of the invention to provide a photographic curtainshutter with a delayed action release which is released by an element ofthe curtain shutter when the latter starts its movement to expose thelm.

Another object of the invention is to provide the roller on which thecurtain tape is wound during the tensioning of the shutter with acam-like member which when the shutter is released and starts itsexposure movement engages a control lever associated with the delayedaction release and thereby causes the control lever to release thedelayed action release. The control lever prevents a further motion ofthe shutter until the delayed action release has run off whereupon thecurtain resumes its movement and exposes the film.

In the drawing:

Fig. 1 illustrates diagrammatically a curtain shutter provided with adelayed action release, the latter being shown in an untensionedposition.

Fig. 2 illustrates the curtain shutter with the delayed action releasein a tensioned position, and

Fig. 3 illustrates the curtain shutter with the delayed action releaseduring the unwinding movement.

In the drawing, the curtain shutter I is pro'- vided with a cam 3 on theconventional roller 2 which takes up the curtain tape during thetensioning of the shutter. A control lever 4 on one hand is adapted tostop under certain conditions, as will be explained presently, therotation of the roller 2 and on the other hand is adapted to lock theanchor-escapement of the delayed action release against operation. Thecontrol lever 4 is slidably and pivotally supported by means of a xedlymounted pin 5, which traverses a slot 6 in the lever 4 between the endsthereof. A spring 'I normally urges the control lever 4 upwardly towardthe cam 3. The control lever 4 is provided with three lateralprojections 8, 9 and I0 as shown. The delayed action release is providedwith an anchor-escapement comprising the oscillatable anchor or pallet II and the toothed wheel I2. A lever I3, which is usually mounted on theoutside of the camera casing, is adapted to be manually rotated in onedirection to tension the delayed action release. The lever I3 isattached to a shaft on which a gear I5 is mounted. A pin I4 on one sideof the gear I5 is adapted to engage the lateral projection I0 at thelower end of the control lever 4 and thus limits the unwinding movementof the delay action release. A spring I9 normally has the tendency torotate the gear I5 in anticlockwise direction until pin I4 engages inthe untensioned position (Fig. l) of the delayed action release thelateral projection I0 of the lever 4.

The delayed action release is tensioned by manually rotating the leverI3 in clockwise direction. When the pin I4 is thus moved away from thelateral projection I0 of the control lever 4, the spring I pulls theentire control lever 4 substantially lengthwise upwardly until the lowerend of the slot 6 rests against the supporting pin 5. In this positionof the control lever 4, as illustrated in Fig, 2, its lateral projection9 engages the anchor I I of the escapement and holds it in a position toprevent an unwinding of the tensioned delayed action release. At thesame time the lateral projection 8 at the uppermost end of the controllever 4 comes to lie under the shoulder 3a of the cam 3, provided thecurtain shutter is in a tensioned position. AIn this position of theparts, as illustrated in Fig. 2, a continuous unwinding movement of theshutter to expose the film in the focal plane of the camera cannot takeplace until the delayed action release has previously been run oil.

When unwinding of the shutter is initiated by depressing theconventional shutter release knob,

l the roller 2 starts to rotate in clockwise direction and the shoulder3a of the cam 3 pushes the control lever 4 lengthwise downwardly adistance limited by the upper end of the slot 6. During this movement ofthe control lever 4, as illustrated in Fig. 3, the lateral projection 9is moved away from the anchor I I and the latter is free to oscillateback and forth so as to control in well known manner the unwinding ofthe delayed action release. During this unwinding movement the pin I4 onthe gear I5 engages the lower end of the control lever 4 and rotates thesame about its piovt 5 in clockwise direction. This has the result thatthe lateral projection 8 of the control lever 4 is moved away from theshoulder 3a of the cam 3 and as soon as the cam 3 is thus released theshutter continues and completes its exposure movement and exposes the lmin the focal plane of the camera. The unwinding movement of the delayedaction release is completed when the pin I4 on the gear I5 engages thelateral projection I0 of control lever as shown in Fig. 1.

The cam 3 is so arranged on the roller 2 that in the unwo-und orreleased position of the shutter the highest point of the cam 3 projectsinto the path of lateral extension 8 of the control lever 4. Under thiscondition, the control lever 4 can not lock the anchor l I of theescapement against movement when the delayed action release is tensionedwithout a prior tensioning of the shutter and the delayed action releasewould immediately begin its unwinding movement as soon as the operatorreleases the manually operable tensioning lever |73.

What I claim "is:

1. The combination of a photographic curtain shutter including a rollerfor taking up the curtain during the tensioning of the shutter, adelayed action release including an .escapement, means actuated by saidroller for releasing the escapement of said previously 'tensioneddelayed action release shortly after 'the curtain shutter upon itsrelease has been set iin motion to execute its exposure movement, saidmeans arresting the motion of said shutter until said delayed actionrelease has run 01T, and means actuated by said delayed action releaseat the end of its unwinding movement-to adjust said first named means topermit a continued motion of said shutter during which the exposuretakes place.

2. The combination of a photographic curtain shi ter provided with aroller on which the curtain is Wound during the tensioning of theshutter, a delayed action release including an escapement, a slidablyand pivotally mounted lever actuated by said roller :fo-r releasing .the-escapement of -said previously tensioned delayed action release shortlyafter the curtain upon its release has been set in motion to perform itsexposure movement, said lever .arresting the motion of said curtainuntil said delayed action release has run oi, and means actuated by said`delayed action release at the end of its unwinding movement to adj-ustsaid lever to cause said curtain to continue and nish its exposuremovement.

3.. The combination of a photographic curtain shutter provided with aroller on which the curtain iswound during the tensioning of theshutter, a cam on said roller, a ldelayed action release including anescapernent, and a slidably pivotally mounted lever actuated by said camvfor releasing the escapement of said previously .tensioned delayedaction release shortly after the curtain upon its release has been setin motion to perform'its exposure movement, said lever arresting themotion of said curtain until said delayed action release has run oi, andmeans actuated Vby said delayed action release at the end .of itsunwinding movementdor operating said lever to cause said curtain tocontinue and nish its exposureV movement.

4. The combination of a photographic curtain shutter provided with aroller on which the curtain is vvvound during the tensioning of theshutter, a delayed action release including an anchorescapemen't, aslidably and rotatably mounted lever, a spring for urging said lever inengagement with the anchor of said anchor-escapement when said delayedaction release is tensioned to prevent an unvvinding of the delayedaction release until the previously tensioned shutter is set in motion,means on said roller actuating said lever to release saidanchor-escapement shortly after said .shutter upon its release has beenset in motion, said lever being maintained in a position in which `itprevents a further motion of the shutter until said delayed actionrelease has run off, and means actuated by said delayed action releaseat the end of its unwinding movement .for moving said lever into aposition in which it permits said shutter to continue and finish itsexposure movement.

5. The combination of a photographic curtain `shutter provided with aroller on which the curtain is Wound during the tensioning of theshutter, a delayed action release including an anchorescapement, afslida-bly and rotatably mounted lever, a :spring for urgi-ng .saidlever in engagement with the anchor of said anchor-escapement when saiddelayed action release is tensioned t0 prevent an unwinding of thedelayed action release until the previously tensioned shutter is set inmotion, means on said roller sldably moving said lever to -release saidanchor-esoapement shortly after said shutter upon its release has beenset in motion, said lever being maintained in a position in which itprevents a further motion of the shutter until said delayed action.release has run 01T, and means on said delayed action release forrotating s aid lever at the end of its unvvinding movement into aposition in which said lever permits said rshutter to continue and nishits exposure movement.

-6. The combination oi a photographic curtain shutter provided with avroller on which the curtain is Wound during the tensioning -of theshutter, a delayed action release including an anchorescapement and amanually oper-able Winding member, a slidably and rotatably mountedlever, a spring for urging .said lever in engagement with the anchor ofsa-id anchor-escapement when said delayed action releaseis tensioned toprevent .an unwinding of the delayed .action release until thepreviously tensioned shutter is `set in motion, means Ion said rolleractuating said lever to release said anchor-escapement shortly aftersaid shutter upon its release has ybeen set in motion, said 4leverybeing maintained ina position in which it prevents a `further motion ofthe shutter until said delayed action release has run oli, and means on.said Winding member Whichat the end of its unwindng movement moves.said lever into a position in which fit permits said shutter tocontinue and finish its exposure movement.

' BRUNO GEHMLICH.

